MINIREVIEW - MECHANISMS OF EGG ACTIVATION - COMPARISON BETWEEN MARINEINVERTEBRATE AND MAMMAL

In most deuterostome eggs, a transient increase in the intracellular f ree calcium concentration (Ca-i) occurs after fertilization and is ess ential for egg activation. How one spermatozoo triggers this calcium s ignal remains an enigma, In the light of our own results, we suggest a model, leading to the calcium signal and common to invertebrate and m ammalian systems, where phosphorylation on tyrosine and phospholipase C gamma (PLC gamma) are interconnected pathways stimulated by a multim olecular complex involving integrins.